<template>
 <div>
     <div class="shopcart">
         <div class="content">
             <div class="content-left">
                 <div class="logo-wrapper">
                     <div class="logo" :class="{'highlight': totalCount>0}">
                         <i class="icon-shopping-cart" :class="{'highlight': totalCount>0}"></i>
                     </div>
                     <div class="num" v-show="totalCount>0"></div>
                 </div>
                 <div class="price" :class="{'highlight': totalPrice>0}">¥{{totalPrice}}</div>
                 <div class="desc">另需配送费¥{{deliveryPrice}}元</div>
             </div>
             <div class="content-right">
                 <div class="pay" :class="payClass">{{payDesc}}</div>
             </div>
         </div>
     </div>
     <div class="ball-container">
         <div v-for="(ball,index) in balls" :key="index">
             <transition
             @before-enter="beforeDrop"
             @enter="dropping"
             @after-enter="afterDrop">
                 <div class="ball" v-show="ball.show">
                     <div class="inner inner-hook"></div>
                 </div>
             </transition>
         </div>
     </div>
 </div>
</template>

<script>
import Bubble from 'components/bubble/bubble'
const BALL_LEN = 10
const innerClsHook = 'inner-hook'
function creteBalls(){
    let ret = []
    for(let i = 0; i  < BALL_LEN; i++){
        ret.push({
            show: false
        })
    }
    return ret
}

 export default {
     name: 'shop-cart',
     props: {
         selectFoods: {
             type: Array,
             default(){
                 return []
             }
         },
         deliveryPrice: {
             type: Number,
             default: 0
         },
         minPrice: {
             type: Number,
             default: 0
         }
     },
     data(){
         return {
             balls: creteBalls()
         }
     },
     created(){
        this.dropBalls = []
    },
     computed: {
        totalPrice(){
            let total = 0
            this.selectFoods.forEach((food) => {
                total += food.price * food.count
            })
            return total
        },
        totalCount(){
            let count = 0
            this.selectFoods.forEach((food) => {
                count+= food.count
            })
            return count
        },
        payDesc(){
            if(this.totalPrice === 0){
                return `¥${this.minPrice}元起送`
            }else if(this.totalPrice < this.minPrice){
                let diff = this.minPrice - this.totalPrice
                return `还差¥${diff}元起送` 
            }else{
                return '去结算'
            }
        },
        payClass(){
            if(!this.totalCount || this.totalPrice < this.minPrice){
                return 'not-enough'
            }else{
                return 'enough'
            }
        }
    },
    methods: {
        drop(el){
            for(let i = 0; i < this.balls.length; i++){
                const ball = this.balls[i]
                if(!ball.show){
                    ball.show = true
                    ball.el = el
                    this.dropBalls.push(ball)
                    return
                }
            }
        },
        beforeDrop(el){
            const ball = this.dropBalls[this.dropBalls
            .length - 1]
            const rect = ball.el.getBoundingClientRect()
            const x = rect.left - 32
            const y = - (window.innerHeight
             -rect.top - 22)
             el.display = ''
             el.style.transform = el.style.webkitTransform = `translate3d(0,${y}px,0)`
             const inner = el.getElementsByClassName(innerClsHook)[0]
             inner.style.transform = el.style.webkitTransform = `translate3d(0,${x}px,0)`
        },
        dropping(el,done){
            this._reflow = document.body.offsetHeight
            el.style.transform = el.style.webkitTransform = `translate3d(0,0,0)`
             const inner = el.getElementsByClassName(innerClsHook)[0]
             inner.style.transform = inner.style.webkitTransform = `translate3d(0,0,0)`
             el.addEventListener('transitionend', done)
        },
        afterDrop(el){
            const ball = this.dropBalls.shift()
            if(ball){
                ball.show = false
                el.style.display = 'none'
            }
        }
    },
    components: {
        Bubble
    }
 }
</script>

<style lang="stylus" scoped>
@import "~common/stylus/mixin"
  @import "~common/stylus/variable"

  .shopcart
    height: 100%
    .content
      display: flex
      background: $color-background
      font-size: 0
      color: $color-light-grey
      .content-left
        flex: 1
        .logo-wrapper
          display: inline-block
          vertical-align: top
          position: relative
          top: -10px
          margin: 0 12px
          padding: 6px
          width: 56px
          height: 56px
          box-sizing: border-box
          border-radius: 50%
          background: $color-background
          .logo
            width: 100%
            height: 100%
            border-radius: 50%
            text-align: center
            background: $color-dark-grey
            &.highlight
              background: $color-blue
            .icon-shopping_cart
              line-height: 44px
              font-size: $fontsize-large-xxx
              color: $color-light-grey
              &.highlight
                color: $color-white
          .num
            position: absolute
            top: 0
            right: 0
        .price
          display: inline-block
          vertical-align: top
          margin-top: 12px
          line-height: 24px
          padding-right: 12px
          box-sizing: border-box
          border-right: 1px solid rgba(255, 255, 255, 0.1)
          font-weight: 700
          font-size: $fontsize-large
          &.highlight
            color: $color-white
        .desc
          display: inline-block
          vertical-align: top
          margin: 12px 0 0 12px
          line-height: 24px
          font-size: $fontsize-small-s
      .content-right
        flex: 0 0 105px
        width: 105px
        .pay
          height: 48px
          line-height: 48px
          text-align: center
          font-weight: 700
          font-size: $fontsize-small
          &.not-enough
            background: $color-dark-grey
          &.enough
            background: $color-green
            color: $color-white
    .ball-container
      .ball
        position: fixed
        left: 32px
        bottom: 22px
        z-index: 200
        transition: all 0.4s cubic-bezier(0.49, -0.29, 0.75, 0.41)
        .inner
          width: 16px
          height: 16px
          border-radius: 50%
          background: $color-blue
          transition: all 0.4s linear
 
</style>
